<ti-alert>success（默认）类型</ti-alert>
<br />
<ti-alert type="prompt">prompt类型</ti-alert>
<br />
<ti-alert type="warn">warn类型</ti-alert>
<br />
<ti-alert type="error">error类型</ti-alert>
<br />
<ti-alert type="simple">simple类型</ti-alert>
